[gobject-introspection] Create a new symbol instead of changing its identifier in place.

[Rico Tzschichholz <ricotz src gnome org>]

commit 75fed99356bbfef17847bc765e916c2d629af956
Author: Tomasz Miąsko <tomasz miasko gmail com>
Date:   Tue Feb 13 00:00:00 2018 +0000

    Create a new symbol instead of changing its identifier in place.
    
    Also free memory associated with macro name when it is unused.

 giscanner/scannerparser.y | 10 ++++++++--
 tests/scanner/regress.h   |  7 +++++++
 2 files changed, 15 insertions(+), 2 deletions(-)
---
diff --git a/giscanner/scannerparser.y b/giscanner/scannerparser.y
index db3aef1f..abfbe065 100644
--- a/giscanner/scannerparser.y
+++ b/giscanner/scannerparser.y
@@ -1508,8 +1508,14 @@ object_macro_define
        : object_macro constant_expression
          {
                if ($2->const_int_set || $2->const_boolean_set || $2->const_double_set || $2->const_string != 
NULL) {
-                       $2->ident = $1;
-                       gi_source_scanner_add_symbol (scanner, $2);
+                       GISourceSymbol *macro = gi_source_symbol_copy ($2);
+                       g_free (macro->ident);
+                       macro->ident = $1;
+                       gi_source_scanner_add_symbol (scanner, macro);
+                       gi_source_symbol_unref (macro);
+                       gi_source_symbol_unref ($2);
+               } else {
+                       g_free ($1);
                        gi_source_symbol_unref ($2);
                }
          }
diff --git a/tests/scanner/regress.h b/tests/scanner/regress.h
index cf0059e4..e1c995a6 100644
--- a/tests/scanner/regress.h
+++ b/tests/scanner/regress.h
@@ -423,6 +423,13 @@ typedef enum
   REGRESS_TEST_EVALUE3 = '0'
 } RegressTestEnumNoGEnum;
 
+/**
+ * REGRESS_TEST_EVALUE_DEPRECATED:
+ *
+ * Scanner used to replace %REGRESS_TEST_EVALUE1 with %REGRESS_TEST_EVALUE_DEPRECATED.
+ */
+#define REGRESS_TEST_EVALUE_DEPRECATED REGRESS_TEST_EVALUE1
+
 _GI_TEST_EXTERN
 const gchar * regress_test_enum_param(RegressTestEnum e);